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Discussion Starter · #1 ·
Hey guys! First post on here so take it easy on me! At a loss with my 01 LB7 fuel leak. Just need some opinions on the issues I’m having. For some background, truck has 152,000 miles, 35,000 on new injectors, 400 miles on new CP3/FPR. I’ve owned the truck for 2 years now and all those repairs were done in the time I owned it. Truck is stock, no tune or anything. About a month ago, truck broke down on the highway, all power lost at once going 55 mph. Fuel leak was puddled in the valley of engine, more drivers side, leaking between the bell housing to the ground. Would crank but wouldn’t turn over. Got it towed to the shop, diagnosed by mechanic as a bad injector pump, bad FPR, and an upper tube blown. All replaced. Got the truck back 2 weeks ago after $2,200 in repairs, drove it fine for the last 2 weeks. Didn’t beat on it or do any hard pulls. Get home from work last night, and leaking fuel in the same spot. Driver side, all over the top of the engine and down between the bell housing to the ground. However, truck still runs and drives for now. I guess my question is, since this leak is in the same location as before it seems, there’s no way my CP3 went bad in 10 days. It makes no sense to me on why there wouldn’t be a leak for 10 days if the problem wasn’t fixed the first time, as it would leak as soon as I got the truck back and wouldn’t turn over. I should add that there’s no fuel in oil, so it doesn’t look like I have a cracked or leaking injector, looks to all be external but I cannot locate the leak itself. Personally, I’m thinking HP lines, return lines or the CP3 at the shop wasn’t correctly installed and something went after 10 days. Sorry for rambling, just wanted to give you guys as much information as possible! Thanks!
 

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I just got done chasing down a fuel leak (hopefully). Turned out to be leaking from the front of the driver's side fuel rail, where the plug threads in. Only way I was able to find it was to run it with the FPR unplugged, which defaults the CP3 to max pressure. Under 23000psi, any leak should make itself obvious in a hurry. If you choose to do this, be extremely careful, as that kind of pressure can do a lot of damage to human flesh. Also, don't run it very long at that pressure. You're probably safer than most with newer injectors & new CP3, but that's a lot of pressure on the HP fuel system of a 20 year old truck.
 

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Discussion Starter · #3 ·
I just got done chasing down a fuel leak (hopefully). Turned out to be leaking from the front of the driver's side fuel rail, where the plug threads in. Only way I was able to find it was to run it with the FPR unplugged, which defaults the CP3 to max pressure. Under 23000psi, any leak should make itself obvious in a hurry. If you choose to do this, be extremely careful, as that kind of pressure can do a lot of damage to human flesh. Also, don't run it very long at that pressure. You're probably safer than most with newer injectors & new CP3, but that's a lot of pressure on the HP fuel system of a 20 year old truck.
Appreciate the response! I’ll have to tear into it this weekend or next and see if I can locate the leak in the rails. Seems like the most logical explanation I’ve found thus far. I’ll check back in once it’s done!
 
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